Matthew McConaughey admits he has a lot less energy

The 43-year-old actor - who sparked concern after he recently dropped 38 pounds from his already lean frame for his role as an AIDS patient in the new movie `The Dallas Buyer`s Club` - revealed his gruelling diet has taken a toll and he can`t wait to eat a cheeseburger.

The father-of-two - whose wife Camilla Alves is pregnant with their third child, told Hitfix: "Overall, [I`ve] probably got 35 percent less energy, but there`s been plateaus. Getting past 170 was really hard, but then once you get [to] 167 the next seven come off easy.

"Got down to 143 and that`s where I want to be. So, once you get past the plateau, your body seems to understand, `OK, this is where we`re leaving now, this is where we are` and so the energy rises.

"Your organs [and] muscles shrink, your organs shrink [and] my stomach has shrunk as well."

The actor also revealed that he lost most of the weight through dieting.

He said: "I`m doing cardio but I`ll tell you what, the more I`ve learned is - and I think it comes with age too - is it`s 90 percent diet. It`s a matter of how much I eat or how little I eat."

He admits he can`t wait to tuck into a gourmet burger once as soon as possible.

He said: "I will have some 70 percent beef, 30 percent fat ground beef, maybe a half-pound cheeseburger with another three types of cheese. I`m going to have buns with butter on both sides, toasted and grilled.

"And then I`m just going to sit back and let the [expletive] just drop on the ground."

sections: Celebrities